This is a phenomenon I've noticed others report as well. It appears that many 90s cartoon series were only produced for one, maybe two years. They were then aired as constant reruns for the following 2-4 years. We were just too young to take note or care, at the time.
I recognized this as a kid and it pissed me off so much. Watching the same episodes of tiny toons over and over was maddening. They were only 3 seasons. At least Animaniacs were around for 5 seasons. They had a good run.
As a kid, I always felt like I missed something because how did they go from Jungle Book to flying fucking cargo planes. I was a stupid child.
To this day, I want the story of how Mowgli returned from the world of man and led an animal uprising, somehow starting them down the path of taking over human society.